an exploration of deep borehole disposal in south korea · that the pwr spent fuel pools begin to...
TRANSCRIPT
1
An Initial Exploration of the Potential for Deep Borehole Disposal of
Nuclear Wastes in South Korea1
Jungmin KANG
Visiting Scholar, SAIS-JHU
Associate Nautilus-ARI, Seoul
(Final Draft, 2 December 2010)
INTRODUCTION
South Korea’s first commercial nuclear power reactor was placed into operation in 1978. Today,
the Republic of Korea (ROK) has twenty reactors in operation: 16 pressurized-water reactors
(PWRs) with a total electric generating capacity of 15 billion watts (GWe) and 4 CANDU
heavy-water reactors (HWRs) with a combined electric-power-generation capacity of 2.8 GWe.
An additional 8 PWRs (with a total capacity of 9.6 GWe) are under construction to be put into
operation by 2016 and plans have been announced to build 11 additional PWRs (15.4 GWe) by
2030.2 That will bring South Korea’s total nuclear generating capacity up to 43 GWe.
As in other countries with nuclear power plants, South Korea’s public has concerns about the
management of radioactive waste. As the available space in-reactor storage pools become
saturated with irradiated fuel assemblies, spent fuel management has become a hot issue. Korea
Hydro and Nuclear Power (KHNP), South Korea’s nuclear utility, has asserted that its nuclear
power plants will begin to run out of spent-fuel storage capacity in 2016.3
At the moment, South Korea’s debate regarding “back-end” nuclear fuel cycle issues (spent fuel
management) is focused on “pyroprocessing,” driven by the Korean Atomic Energy Research
Institute (KAERI). This is partially because Japan has established its own spent fuel reprocessing
capacity, and because, although a reprocessing plant could not be put into operation by the time
that the PWR spent fuel pools begin to fill up, the expectation that the fuel will be reprocessed
could provide a justification for establishing central storage for spent fuel near the site where the
reprocessing plant would be built. Whether or not it pursues reprocessing, South Korea needs
sites to accommodate geological repositories for its spent fuel and/or for the high level wastes
(HLW) produced during reprocessing.
The deep borehole disposal concept has been recently receiving global attention due to its
potential technical and cost advantages when compared with “normal” geologic disposal. The
deep borehole concept involves drilling into crystalline basement rocks to a depth of 3 to 5-km,
then placing waste canisters in the bottom 1-2 kilometers of the boreholes and capping the
borehole such that the wastes are permanently isolated..
1 This study was funded by Nautilus Institute from a grant from the MacArthur Foundation.
2 National Energy Committee, The 1st National Energy Basic Plan (2008-2030), August 2008 (Korean). Includes 4
PWRs (5.6 GWe) to be brought into operation between 2017 and 2021, Ministry of Knowledge Economy, The 4th
Basic Plan of Long-Term Electricity Supply and Demand (2008 ~ 2022), December 2008. 3 Ki-Chul Park, "Status and Prospect of Spent Fuel Management in South Korea," Nuclear Industry, August 2008
(Korean).
2
This report briefly explores the concept of using deep borehole disposal in South Korea. It
begins with a review of international experience to date in evaluating the prospects of deep
borehole disposal of nuclear wastes, then provides an initial review of the geologic suitability of
the technology for Korea. The paper offers a review of the institutions, laws, and practices
related to spent fuel management in the ROK, and offers tentative conclusions as to the
applicability of deep borehole disposal for the nation and the Korean Peninsula.
DEEP BOREHOLE DISPOSAL (DBD)
History of DBD
Although US evaluation of DBD began in the 1950s,4 more recent studies, beginning in the
1990s, have been more significant. A recent MIT study summarized principal earlier studies on
DBD as shown in Table 1.5 A 2003 MIT report recommended that DBD for spent fuel had the
potential to significantly reduce risk compared to mined repositories, leading to an on-going
project by the joint Sandia National Labs and MIT group to explore DBD as a possible
alternative to the (developed but not completed, and recently cancelled) mined repository at
Yucca Mountain, in Nevada.6
4 Peter Swift, "Goals for a Deep Borehole Disposal Workshop," SNL-MIT Workshop on Deep Borehole Disposal,
Washington, DC, March 15, 2010. Available in
www.mkg.se/uploads/SNL_MIT_borehole_workshop_report_final_100507.pdf. 5 Benyamin Sapiie and Michael J. Driscoll, A Review of Geology-Related Aspects of Deep Borehole Disposal of
Nuclear Wastes: For the MIT Study on The Future of the Nuclear Fuel Cycle, MIT-NFC-TR-109, August 2009. 6 Fergus Gibb, "Deep borehole disposal (DBD) methods," Nuclear Engineering International, 25 March 2010
3
Table 1: Summary Comparison of Deep Borehole Concepts
Concept of DBD
In the DBD concept, a borehole is drilled in crystalline basement rocks to a depth on the order of
5 km. The bottom a 1-2 km of the borehole is used as the waste disposal zone, which might hold
200-400 canisters, as shown in Figures 1 and 2.7 Figure 1 implies that the region of crystalline
basement rocks is hydraulically decoupled from regions of groundwater flow. As shown in
Figure 2, one such borehole, for example, could hold about 100-200 tonne heavy-metal (tHM) of
pressurized water reactors (PWRs) spent fuel.
7 Patrick V. Brady et al., Deep Borehole Disposal of High-Level Radioactive Waste, SAND2009-4401, August
2009; N. Chapman and F. Gibb, "A truly final waste management solution," Radwaste Solutions 10/4, p.26-37
(2003); Michael J. Driscoll, "A Case for Disposal of Nuclear Waste in Deep Boreholes," SNL-MIT Workshop on
Deep Borehole Disposal, Washington, DC, March 15, 2010.
4
Figure 1: Conceptual Model for Deep Borehole Disposal
DBD would have potential advantages over normal geologic disposal, as it would place waste
canisters at greater depths with less dynamic hydro-geological conditions, which increases
confidence that eventual impacts on the biosphere by the radioactive waste can be avoided or
substantially reduced. Low permeability in the deep crystalline basement rocks and the high
salinity in the deep aquifers found there suggest that the chances of interaction of wastes with
groundwater should be minimal. Crystalline basement rocks are relatively common at depths of 2
km to 5 km in many countries, leading to wider availability of suitable sites for DBD. In addition
to greater safety through better isolation of wastes from the biosphere, greater security against
terrorist diversion of wastes disposed of in DBD and better cost-effectiveness would be
additional potential benefits.8
8 Bill W. Arnold et al., "Into the deep," Nuclear Engineering International, 25 March 2010; Gibb, F.G.F., Taylor,
K.J. and Burakov, B.E. "The 'granite encapsulation' route to the safe disposal of Pu and other actinide," Journal of
Nuclear Materials, Volume 374 (3), p.364 – 369 (2008). As shown in Figure 2, the waste at the bottom of the
borehole would be protected by 3-4 km of clay and concrete plugs and backfill, requiring a major drilling operation
to penetrate to where the wastes have been buried, and making it highly unlikely that a terrorist group could access
the wastes undetected.
5
Figure 2: Schematic of Deep Borehole Disposal
Site Selection
Heiken et al. list four factors that define an ideal site for DBD as follows.9
- Crystalline rock at the surface or within 1 km of the surface.
- A region that is tectonically stable.
- An area located away from population centers.
- A region not near international borders (i.e. >200 km)
Retrievability
The difficulty of retrieving wastes after final repository closure is one of the contentious issues
with respect to DBD. The 2009 MIT report summarizes the main arguments for and against
9 Heiken, G, Woldegabriel, G, Morley, R, Plannerer, H and Rowley, J. Disposition of excess weapons plutonium in
deep boreholes – Site selection handbook. Report of the Los Alamos National Laboratory, Report LA-13168-MS.
1996.
6
retrievable variants of DBD, as shown in Table 2, and reaches the conclusion that non-
retrievability/permanent disposal is preferred.10
Table 2: Nuclear Spent Fuel Emplacement Options and Strategies
Borehole Drilling Experience
A 2009 MIT report summarizes borehole drilling experience in the past more recently, as
described in Table 3.11
A 2009 Sandia National Laboratory (US) study estimates a cost of about
$20 million for construction of each 5 km-depth borehole, which would require about 110 days
to drill, not including emplacement operations, licensing, and other activities. This estimate
assumes the use existing drilling technologies.12
10
Benyamin Sapiie and Michael J. Driscoll, A Review of Geology-Related Aspects of Deep Borehole Disposal of
Nuclear Wastes: For the MIT Study on The Future of the Nuclear Fuel Cycle, MIT-NFC-TR-109, August 2009. 11
Benyamin Sapiie and Michael J. Driscoll, A Review of Geology-Related Aspects of Deep Borehole Disposal of
Nuclear Wastes: For the MIT Study on The Future of the Nuclear Fuel Cycle, MIT-NFC-TR-109, August 2009. 12
Patrick V. Brady et al., Deep Borehole Disposal of High-Level Radioactive Waste, SAND2009-4401, August
2009.
7
Table 3: Experience with Deep Boreholes into Crystalline Rock
SUITABILITY OF THE KOREAN PENINSULA FOR GEOLOGIC DISPOSAL
Appropriate siting of DBD is very important to assure the safety of disposal of spent fuel or
HLW. The site used should have characteristics suitable to prevent or retard the potential
movement of radionuclides from the disposal system to the biosphere. The natural geologic
characteristics of the site play an important role in the disposal concept.13
A past study14
provides the following guidelines on desirable site characteristics of DBD, ideally
favoring a combination of:
(1) crystalline rock at the surface or within 1 km of the surface;
(2) a region that is tectonically stable;
(3) an area located away from population centers; and
(4) a region not near international borders.
13
IAEA, Siting of Geological Disposal Facilities: A Safety Guide, Safety Series No. 111-G-41 (1994). 14
At an ideal site for DBD, it must be demonstrated that there is no fluid movement from the bottom of the borehole
at a depth of 4 kilometers and there will be no significant migration over the next million years. Grant Heiken et al.,
Disposition of Excess Weapon Plutonium in Deep Boreholes: Site Selection Handbook, LA-13168-MS, September
1996.
8
Geology of the Korean Peninsula
The Korean peninsula is located between the Eurasian continent and the west Pacific mobile belt.
More than half of the exposed area of the peninsula consists of Precambrian metamorphic rocks
and Paleozoic-Mesozoic plutonic rocks, while sedimentary and volcanic rocks of Paleozoic and
Mesozoic era are distributed on those basements accompanied with tectonic movement.15
Based on these lithological characteristics, formation stages and continuity of geological history,
a division of tectonic provinces on the Korean peninsula is shown in Figure 3.16
According to a KAERI study,17
the massif and fold belts are of primary interest among the
tectonic units in Korean peninsula with regard to radioactive waste disposal. Nangnim massif,
Kyonggi massif, and Sobaeksan massif are Archean-early Proterozoic massif. Hambuk fold belt
and Okchon fold belt are upper Proterozoic-upper Paleozoic fold belt. Kyonggi massif,
Sobaeksan massif and Okchon fold belt are located in the southern part of the Korean peninsula.
It is desirable that DBD facilities be located away from population centers. Figure 4 shows
population densities in South Korea as of 2005.18
Combining consideation of the tectonic
provinces and the areas of low population density in South Korea provides a rough idea of which
areas of the ROK might be suitable sites for DBD.
15
C.S.Kim et al., "Lithological Suitability for HLW Repository in Korea," Proceedings of Symposium entitled
Technologies for the Management of Radioactive Waste from Nuclear Power Plants and Back End Nuclear Fuel
Cycle Activities, Taejon, Republic of Korea, 30 August - 3 September 1999. 16
Ibid. 17
Ibid. 18
Modified from "Statistics Korea" (http://atlas.ngii.go.kr/map/territory.jsp?fcode=03)
9
Figure 3: Tectonic Provinces in Korean Peninsula
10
Figure 4: Population Density Map of South Korea in 2005 (Legend: persons per sq. km)
Regional Fractures in South Korea
In South Korea, there are a few large-scale tectonic fractures, while small-scale fractures are
evenly distributed throughout the southern peninsula, as shown in Figure 5.19
19
Ibid.
11
Figure 5: Fracture Map Superimposed on Tectonic Provinces in South Korea
Seismicity
As the Korean peninsula is located in the area where the Eurasian plate contacts with the west
Pacific mobile belt, earthquakes in Korea are ascribed to intra-plate seismicity.20
Table 4 and
Figure 6 show historical seismicity records for the Korean peninsula.21
Even Though low-level
earthquake activity has been a historical feature of the Korean peninsula, a large portion of the
earthquakes that have occurred have been in the southern part of the peninsula.
20
Ibid. 21
Wenjie Zhai et al., "Research in historical earthquakes in the Korean peninsula and its circumferential regions,"
Acta Seismologica Sinica, Vol.17, No.3, p.366-371, May 2004.
12
Table 4: Statistics of Magnitude >4.75 Historical Earthquakes on the Korean Peninsula
Figure 6: Epicentral Distribution of Historical Earthquakes in the Korean Peninsula
Existing Concept of Spent Fuel Disposal System in South Korea (Mined Repository)
For comparison purpose, this study describes below a concept of a Korean disposal system
designed by Korea Atomic Research Institute (KAERI). KAERI’s conceptual geologic
13
repository is designed to be located in granite rocks at depth of 500 m, although the real
repository site has not been chosen as yet. The layout and other specifics of the repository design
are provided in Figure 7 and Table 5.22
The total capacity of spent fuels disposal in the
repository is assumed to be 20,000 tHM of PWR spent fuel and 16,000 tHM of CANDU spent
fuel.
According to the KAERI research referenced above, the peak temperature of the bentonite buffer
material in which double-walled metal canisters containing spent fuels are buried should be
lower than 100 ºC to assure the long term integrity of its physical and chemical properties. With
this constraint, the distance between the parallel tunnels in the repository is 40 m, and the
minimum distance between two deposition holes for PWR canisters and CANDU canisters are 6
m and 3 m, respectively. These distances are calculated assuming that heat generation is 1,540
W for the PWR canister and 760 W for the CANDU canister, based on spent fuel cooling times
of 40 and 30 years, respectively prior to introduction into the repository. This concept of disposal
system was designed to be used to evaluate the feasibility of a high-level waste/spent fuel
disposal system for the ROK, and to help to formulate data needed to carry out a long-term
safety analysis.23
Figure 7: Layout of the Korean Reference Disposal System
Table 5: Length and the Number of Disposal Tunnels
22
Jongyoul Lee et al., "Concept of a Korean Reference Disposal System for Spent Fuels," Journal of Nuclear
Science and Technology, Vol.44, No.12, p.1565-1573, 2007. Available as
http://www.jstage.jst.go.jp/article/jnst/44/12/1565/_pdf. 23
Ibid.
14
SPENT FUEL MANAGEMENT IN SOUTH KOREA
Institutional Framework in the Radioactive Waste Management
With regard to the governmental organizations concerned with radioactive waste, the main
administrative authorities in the ROK are the Ministry of Knowledge Economy (MKE), which
supervises the nuclear power program, and the Ministry of Education, Science and Technology
(MEST), which is responsible for nuclear safety regulations including the licensing of nuclear
facilities. The Atomic Energy Committee (AEC) under the jurisdiction of the Prime Minister is
the supreme organization for decision-making on national nuclear policies. The Nuclear Safety
Commission (NSC) under the jurisdiction of MEST is responsible for matters concerning the
safety of nuclear facilities and radioactive waste management. MEST is also responsible for
developing licensing criteria for the construction and operation of radioactive waste disposal
facilities, developing technical standards for operational safety measures, and for assuring safe
management of radioactive waste at every stage of the site selection, design, construction,
operation, closure and post-closure of radioactive waste disposal facilities. MKE also develops
and implements management policies regarding radioactive waste treatment, storage and
disposal. These policies are prepared by MKE and deliberated by the AEC before
implementation.24
Legal Framework in the Radioactive Waste Management
Key ROK National laws related to spent fuel and radioactive waste management are the Atomic
Energy Act (AEA) and the Radioactive Waste Management Act (RWMA). The AEA provides
for matters concerning safety regulations, including permission for construction and operation of
radioactive waste disposal facilities. The RWMA, which determines all aspects of managing
radioactive waste, was announced on March 28, 2008, and was enacted on March 31, 2010.
Based on the RWMA, the Korea Radioactive Waste Management Organization and the
Radioactive Waste Management Fund were established. According to the RWMA, KHNP, the
utility company, should annually deposit to the Fund the cost of decommissioning of nuclear
24
radioactive waste management in Rep. of Korea
(http://www.nea.fr/rwm/profiles/Korea%20report%202010%20web.pdf)
15
power plants, disposal of low and intermediate level waste (LILW), and spent fuel management.
Figure 8 shows the financing structure for radioactive waste management in South Korea.25
Current Practice in the Management of the Spent Fuel
At its 253rd
meeting in 2004, the AEC announced that national policy for spent fuel management
would be decided later in consideration of progress of domestic and international technology
development, and that spent fuel would be stored at a reactor site by 2016 under KHNP’s
responsibility.26
South Korea has not decided whether to directly dispose of or recycle spent fuel.
Currently, South Korea has no national plan on geologic disposal of spent fuel or HLW.
Therefore there are no regulatory and licensing issues relevant to DBD in South Korea either.
Figure 8: Financing Structure of Radioactive Waste Management in South Korea
Status and Prospect of Nuclear Power in South Korea
As described in the introductory part of this report, currently in South Korea 16 PWRs and 4
HWRs are in operation, with 8 PWR units under construction and due to be completed by 2016,
and 11 more PWRs to deployed by 2030. Table 6 shows the generating capacities and expected
initial operating dates of South Korea’s power reactors through 2021.27
25
Ibid. 26
253rd
meeting of Korea AEC in 2004. See, for example, Ministry of Education, Science & Technology, Korean
Third National Report under the Joint Convention on the Safety of Spent Fuel Management and on the Safety of
Radioactive Waste Management, dated October, 2008, and available as
www.kins.re.kr/pdf/Korean%20Third%20National%20Report%202008.pdf. 27
http://www.khnp.co.kr/en/03000100; http://www.khnp.co.kr/en/030100; Ministry of Knowledge Economy, The
4th Basic Plan of Long-Term Electricity Supply and Demand (2008 ~ 2022), December 2008.
16
Table 6: Current and Planned Nuclear Power Capacity in South Korea through 202128
Site Unit Type Capacity
(GWe) Operation
(year.month) Pool storage
capacity
(tHM) a
Programmed
capacity increase
from re-racking
(tHM)
Kori Kori-1
Kori-2
Kori-3
Kori-4
Shin-Kori-1
Shin-Kori -2
Shin-Kori -3
Shin-Kori -4
Shin-Kori -5
Shin-Kori -6
Subtotals
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
0.587
0.650
0.950
0.950
1.000
1.000
1.400
1.400
1.400
1.400
10.737
1978. 4
1983. 7
1985. 9
1986. 4
2010.12
2011.12
2013. 9
2014. 9
2018.12
2019.12
158.8
327.6
270.9
270.9
428.7
428.7
625.7
625.7
625.7
625.7
4388.4
696.4
697.4
_____
1393.8
Yonggwang Yonggwang-1
Yonggwang-2
Yonggwang-3
Yonggwang-4
Yonggwang-5
Yonggwang-6
Subtotals
PWR
PWR
PWR
PWR
PWR
PWR
0.950
0.950
1.000
1.000
1.000
1.000
5.900
1986. 8
1987. 6
1995. 3
1996. 1
2002. 5
2002.12
270.9
270.9
215.4
215.4
224.9
224.9
1422.4
697.4
186.8
268.3
268.3
_____
1420.8
Ulchin Ulchin-1
Ulchin-2
Ulchin-3
Ulchin-4
Ulchin-5
Ulchin-6
Shin-Ulchin-1
Shin-Ulchin-2
Shin-Ulchin-3
Shin-Ulchin-4
Subtotals
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
0.950
0.950
1.000
1.000
1.000
1.000
1.400
1.400
1.400
1.400
11.500
1988. 9
1989. 9
1998. 8
1999. 12
2004. 7
2005. 4
2015. 12
2016. 12
2020. 6
2021. 6
144.9
144.9
215.4
215.4
224.9
224.9
625.7
625.7
625.7
625.7
3673.2
297.7
273.7
352.6
352.6
_____
1276.6
Wolsong
CANDUs
Wolsung-1
Wolsung-2
Wolsung-3
Wolsung-4
Subtotals
HWR
HWR
HWR
HWR
0.679
0.700
0.700
0.700
2.779
1983. 4
1997. 7
1998. 7
1999. 10
842.7
736.8
736.8
736.8
3053.1
(6,930+ dry-cask
storage as of 2009)
29
Wolsung
PWRs
Shin-Wolsung-1
Shin-Wolsung-2
Subtotals
PWR
PWR
1.000
1.000
2.000
2012. 3
2013. 1
504.8
504.8
1009.6
a Pool storage capacity measured in metric tons of original uranium in the fuel (tons heavy metal or tHM). These
values do not include the pool capacity for a full reactor core that is held open in case all the fuel in the current
reactor core has to be unloaded quickly.
28
J.H. Mok et al., Examination on Amount of Spent Fuel Stored and Verification on Saturation Time of Pool
Capacities, Kookmin University, May 2009 (in Korean). 29
Jongwon Choi, “R&D Program for Spent Fuel Storage and Disposal,” Korea Atomic Energy Research Institute,
27 May 2009.
17
Status and Prospect of Spent Fuel Generation
As of the end of 2008, 4,866 tons of spent PWR fuel and 6,082 tHM of spent HWR fuel were
stored in the spent fuel storage facilities at South Korea’s four NPP sites. Table 7 shows the
spent fuel inventories at the four sites as of the end of 2008. According to an analysis by the
operator, KHNP, the saturation dates for the current storage at the Kori, Yonggwang and Ulchin
sites for spent PWR fuel, and at the Wolsong site for spent HWR fuel, will be 2016, 2021, 2018
and 2017 respectively.30
Table 7: Inventory of spent fuels in South Korea as of the end of 200831
Kori site
(tHM)
Yonggwang site
(tHM)
Ulchin site
(tHM)
Wolsong site
(tHM)
1,768 1,732 1,366 2,912 in pools
3,170 in dry casks
Projections of spent fuel generation depend on the capacity factors of the reactors (that is, what
fraction of the time they operate and at what average fraction of their nominal capacities), and
the burnup of spent fuel (that is, the number of megawatt-days of heat that can be generated from
a kilogram of fuel before it is “spent”). The average discharged burnup level for spent PWR fuel
is around 50,000 MWd/tHM in today’s reactors.32
Heavy-water reactors are fueled with natural
uranium, and the burnup rate is about 7,100 MWd/tHM. Assuming that all NPPs have thermal
efficiencies of 33% and capacity factors of 90 percent, which is reasonably consistent with ROK
experience, the projections of cumulative spent fuel generation in South Korea from reactors
completed by 2030 are given in Figure 9 for the years 2010 through 2050. This study estimates
that approximately 51,000 tons of spent PWR fuel and approximately 20,000 tHM of spent HWR
fuel will be generated over the entire lifetimes (that is, until each unit is decommissioned,
whether before or after 2050) of the 35 PWR and 4 HWR units that will be deployed by 2030.
30
Ki-Chul Park, "Status and Prospect of Spent Fuel Management in South Korea," Nuclear Industry, August 2008
(in Korean). 31
J.H. Mok et al., op. cit. 32
Based on an initial uranium enrichment in fresh PWR fuel of 4.5 percent, J.H. Mok et al., Examination on Amount
of Spent Fuel Stored and Verification on Saturation Time of Pool Capacities, Kookmin University, May 2009
(Korean); The Future of Nuclear Power: An Interdisciplinary MIT Study, MIT, p. 119 (2003).
18
Year
2010 2020 2030 2040 2050
Invento
ry (
tHM
)
0
10000
20000
30000
40000
50000
60000
PWR
CANDU
TOTAL
Figure 9: Cumulative Inventory of Spent Fuel Generation in South Korea from Reactors
Deployed by 203033
Rough Cost Estimation of DBD Implementation
To estimate what the DBD option might cost as a spent fuel disposal option for South Korea, the
author made the assumption that 200-400 canisters containing a total of about 100-200 tHM of
spent PWR fuel can be accommodated in a borehole in crystalline basement rocks on the order of
5 km deep with a 1-2 km long waste disposal zone, while one borehole might hold about 1,600-
3,200 canisters containing about 32-64 tHM spent HWR fuel, assuming a canister length of 0.6
m.34
Table 8 shows the roughly-estimated annual costs of DBD construction through 2050 to
accommodate the ROKs spent fuel that has cooled for approximately 30 years to that date.
These costs are, based on a cost of about $20 million for construction of each 5 km-depth
33
The assumed 60 and 50-year operating lives for PWRs and HWRs, respectively, are based on the 1st National
Energy Basic Plan (2008-2030). 34
Typical HWR fuel, for example, in a CANDU fuel bundle, is about 50 cm in length, 10 cm in diameter, and
weighs about 20 kg HM. http://en.wikipedia.org/wiki/Nuclear_fuel#CANDU_fuel.
19
borehole, as included in the 2009 Sandia National Laboratory study referenced above35
. The
costs shown do not include any additional costs for items such as administration cost, and with
no real escalation (or reduction due to learning) in costs assumed. 2030 is assumed to be the
start year for borehole disposal. Table 8 shows the amount of spent fuel disposed of annually, as
well as the number of boreholes needed to dispose of cooled spent fuels using DBD from 2030
through 2050. Spent fuel disposal by year is based on historical spent fuel quantities removed
from ROK reactors through 2008. So, for example, the quantity of PWR fuel shown as being
sent to borehole disposal in 2033 is the amount removed from reactor cores in 2003. After 2008,
the estimates of annual new spent fuel production implied by Figure 9, plus 30 years, are used to
estimate the amount of spent fuel sent to disposal.
Due to the larger volume of spent fuel discharged, the cumulative cost of DBD for CANDU
(HWR) spent fuel for 2030 – 2050 is three times greater than that of PWR spent fuel, despite the
fact that PWRs produce much more of the ROK’s electricity than HWRs. To reduce the cost of
DBD, CANDU spent fuel needs to be more densely packed into canisters before it is subjected to
deep borehole disposal.
Table 8: The estimated annual cost of DBD construction from 2030 through 2050
Year PWRs CANDUs
Spent
Fuel
(tHM)
# of Boreholes M$ Spent Fuel
(tHM)
# of Boreholes M$
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2450
247
258
257
185
298
297
336
538
297
317
338
357
405
432
461
489
488
516
545
572
12.3 – 24.5
1.2 – 2.5
1.3 – 2.6
1.3 – 2.6
0.9 – 1.9
1.5 – 3.0
1.5 – 3.0
1.7 – 3.4
2.7 – 5.4
1.5 – 3.0
1.6 – 3.2
1.7 – 3.4
1.8 – 3.6
2.0 – 4.1
2.2 – 4.3
2.3 – 4.6
2.4 – 4.9
2.4 – 4.9
2.6 – 5.2
2.7 – 5.5
2.9 – 5.7
245.0 – 490.0
24.7 – 49.4
25.8 – 51.6
25.7 – 51.4
18.5 – 37.0
29.8 – 59.6
29.7 – 59.4
33.6 – 67.2
53.8 – 107.6
29.7 – 59.4
31.7 – 63.4
33.8 – 67.6
35.7 – 71.4
40.5 – 81.0
43.2 – 86.4
46.1 – 92.2
48.9 – 97.8
48.8 – 97.6
51.6 – 103.2
54.5 – 109.0
57.2 – 114.4
2329
380
390
390
401
390
390
1312
102
390
390
390
390
390
390
390
390
390
390
390
390
36.4 – 72.8
5.9 – 11.9
6.1 – 12.2
6.1 – 12.2
6.3 – 12.5
6.1 – 12.2
6.1 – 12.2
20.5 – 41.0
1.6 – 3.2
6.1 – 12.2
6.1 – 12..2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
6.1 – 12.2
727.8 – 1455.6
118.8 – 237.5
121.9 – 243.8
121.9 – 243.8
125.3 – 250.6
121.9 – 243.8
121.9 – 243.8
410.0 – 820.0
31.9 – 63.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
121.9 – 243.8
Total 10,083 50.4 – 100.8 1,008 – 2,017 10,758 168.1 – 336.2 3,362 – 6,724
35
Patrick V. Brady et al., Deep Borehole Disposal of High-Level Radioactive Waste, SAND2009-4401, August
2009.
20
Overall, Table 8 shows that the undiscounted cost of disposing of the spent fuel generated in the
ROK and sufficiently cooled (30 years) for DBD disposal are in the range of about $4 to $9
billion from 2030 through 2050. Put into perspective, this cost amounts to about $0.001 to
$0.002 per kWh of electricity generated in nuclear power plants in the ROK through 2020.
Recent Public Opinion of Local Communities
The author of this report, Jungmin Kang, undertook a week-long research trip to South Korea’s
four NPPs sites in mid-September 2010. The followings are his key findings from the trip.
- The local people36
who live near nuclear power plants sites are not aware of the safety
superiority of dry cask storage of spent fuel, when compared with pool storage, and are
also not aware of the potential safety superiority of deep borehole disposal of spent fuel,
compared with normal geologic disposal.
- Local people showed an interest in considering on-site dry cask storage of spent fuel as
well as possible in-situ deep borehole disposal if the safety of those options were assured
by reliable experts and the local sites are properly compensated financially.
- Educating local people will be very important to achieving on-site dry cask storage of
spent fuel as well as possibly in-situ deep borehole disposal in South Korea.
Political and Legal Issues
There would be political implication of implementing DBD of spent fuel in South Korea. The
South Korean nuclear fuel cycle community, represented by KAERI, strongly insists on
pyroprocessing as its favored alternative for future spent fuel management in the ROK, and
would not support any kind of direct disposal of spent fuel in South Korea. Locals living near
nuclear facilities, on the other hand, have as their major goal safe geologic disposal of spent fuel
and/or HLW.
There are no current legal issues that might affect the practicality of borehole disposal of spent
fuel in South Korea, since the current South Korean Atomic Energy Act does not includes any
articles relevant to spent fuel disposal.
International Cooperation
A 2010 MIT study recommends research and development of deep borehole disposal for spent
fuel and HLW management,37
based on recent relevant research including a collaborative study
done by MIT and Sandia National Laboratories.38
36
Local people mentioned at this report are representatives of non-governmental organizations based near reactor
sites who Jungmin Kang met during his trips in mid-September 2010. 37
MIT, The Future of the Nuclear Fuel Cycle: An Interdisciplinary MIT Study (2010). Available as
web.mit.edu/mitei/docs/spotlights/nuclear-fuel-cycle.pdf.
21
The US – Japan Joint Nuclear Energy Action Plan, a process started in 2007, reached a similar
conclusion in its May 2010 report of Phase I of its Waste Management Working Group, as
follows:39
“… we view the deep borehole disposal approach as a promising extension of geological
disposal, with greater siting flexibility and the potential to reduce the already very low risk of
long-term radiation exposure to still lower levels without incurring significant additional costs.”
Based on the results of these studies, opportunities for cooperation jointly with the US and Japan
on DBD would help to spur interest in the South Korean nuclear (scientific and policy)
community in DBD evaluation and consideration.
TENTATIVE CONCLUSIONS
Considering its potential safety superiority compared with normal geologic disposal, deep
borehole disposal could be an alternative, which could be more acceptable to local communities,
for the eventual disposal of spent fuel and/or HLW in South Korea.
Further study needs to be done to identify relevant technical issues, as well as to obtain
comprehensive public and local opinions on the deep borehole disposal possibility for the ROK.
38
Patrick V. Brady and Michael J. Driscoll, Deep Borehole Disposal of Nuclear Waste: Report from a Sandia-MIT
Workshop on March 15, 2010 in Washington, DC. Dated May 7, 2010, available as
www.mkg.se/uploads/SNL_MIT_borehole_workshop_report_final_100507.pdf. 39
Information Basis for Developing Comprehensive Waste Management System – US-Japan Joint Nuclear Energy
Action Plan Waste Management Working Group Phase I Report, FCR&D-USED-2010-000051, Published Jointly as
JAEA-Research-2010-015, May 2010. Available as www.ipd.anl.gov/anlpubs/2010/05/67013.pdf.